Imported From: https://issues.scala-lang.org/browse/SI-9957?orig=1
Reporter: @Atry
Affected Versions: 2.10.6, 2.11.8, 2.12.0-RC1

@som-snytt said:
I didn't try, but Javadoc says "The returned map is typically case-sensitive on all platforms."

@Atry said:
I mean java.lang.System.getenv(String)

currently env returns a Map. in order to make it case-insensitive, we'd have to add new API. in 2.13, scala.sys will become its own module, at which point this could be addressed if someone cares to.

closing since scala.sys issues will no longer be tracked here in scala/bug. I've made a "module:scala.sys" label so we can find relevant issues once the module has its own repo

@SethTisue Is this still the relevant place to talk about this? I've noticed the issue today by chance and I was thinking to use System.getenv(String) (which behaves correctly on Windows), doing something along these lines, so to not have to add a new API or introduce a breaking change (signature-wise, at least, I hope no one is relying on this behavior, which I believe can be anyhow considered incorrect):

  private final class Env extends immutable.Map[String, String] {

    override def +[V1 >: String](kv: (String, V1)): Map[String, V1] =
      iterator.toMap + kv

    override def get(key: String): Option[String] =
      Option(System.getenv(key))

    override def iterator: Iterator[(String, String)] =
      JavaConverters.mapAsScalaMap(System.getenv()).iterator

    override def -(key: String): Map[String, String] =
      iterator.toMap - key

  }

  /** An immutable Map representing the current system environment.
   *
   *  @return   a Map containing the system environment variables.
   */
  def env: immutable.Map[String, String] = new Env

I noticed that env is currently a def, so it may be desirable to turn Env in a final class and env back to a def, but the reason behind it is unclear to me (maybe something related to the behavior of the Java runtime but I'm not sure).

If this is not the right place to discuss about this I'd be very happy to move the discussion somewhere else. 😉

There is a code comment suggesting they want to remove the related SystemProperties map in favor of a simple forwarder to getProperty.

I'd expect the same thinking to apply here, with the additional prejudice that the semantics for case-sensitivity are strange.

An updated map would lose its special get.

Interacting with process environment is via processBuilder.environment in java and scala.sys.process just lets you supply extra env mappings.

The proposed solution does have the virtue of not changing the API.

Shall we just add a withDefault to the original map?
scala/scala#8508

I couldn't think of how it wouldn't be weird asymmetry, "get didn't return my "shell"." "You have to use apply." "Oh, yeah."

Your argument applies to all usage of withDefault.

I couldn't think of how it wouldn't be weird asymmetry, "get didn't return my "shell"." "You have to use apply." "Oh, yeah."

It's exact the same behavior as Java System.getenv().get("path") vs System.getenv("path").

I agree with the previous comments, that conventionally you'd use apply for the special "platform-specific" behavior. I'm too lazy to exercise the behavior, as I am lying in bed with my Mac and not sitting out in the other room with the test bed windoze box.